Angiotensin II is a natural substance in your body that affects your cardiovascular system in many ways, such as by narrowing your blood vessels. This narrowing can increase your blood pressure and force your heart to work harder. Angiotensin II also starts the release of a hormone that increases the amount of sodium and water in your body, which can lead to increased blood pressure. Angiotensin II can also thicken and stiffen the walls of your blood vessels and heart.

Several angiotensin II receptor blockers are available. Which one is best for you depends on your health and the condition being treated.

Examples of angiotensin II receptor blockers include:

Azilsartan (Edarbi)

Candesartan (Atacand)

Eprosartan (Teveten)

Irbesartan (Avapro)

Losartan (Cozaar)

Olmesartan (Benicar)

Telmisartan (Micardis)

Valsartan (Diovan)

Doctors prescribe these drugs to prevent, treat or improve symptoms in a variety of conditions, such as:

High blood pressure

Heart failure

Kidney failure in diabetes

Chronic kidney diseases

Hardening and thickening of the skin (scleroderma)

Few people have side effects when taking angiotensin II receptor blockers, but possible side effects may include:

Headache

Dizziness

Lightheadedness

Nasal congestion

Back and leg pain

Diarrhea

There have been some reports of intestinal problems known as sprue-like enteropathy in those taking olmesartan. Talk to your doctor if you develop severe diarrhea or experience significant weight loss while taking olmesartan.

Rare but more-serious side effects include:

Kidney failure

Liver failure

Allergic reaction

A drop in white blood cells

Localized swelling of tissues (angioedema)

Because angiotensin II receptor blockers can cause birth defects, don't take them if you are pregnant or plan to become pregnant.

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